It is often desirable to convert a DC battery voltage into a 110 volt alternating current. Devices which perform such functions are generally termed voltage inverters, and most often are designed to operate from a 12 volt automobile battery to produce household current, for example to power television sets or microwave ovens in recreational vehicles. Such inverters are also extremely useful as backup power sources for electrical office equipment, electronic cash registers, minicomputers and even sump pumps.